diff options
| -rw-r--r-- | Changelog | 1 | ||||
| -rw-r--r-- | doc/filters.texi | 54 | ||||
| -rw-r--r-- | libavfilter/Makefile | 1 | ||||
| -rw-r--r-- | libavfilter/allfilters.c | 1 | ||||
| -rw-r--r-- | libavfilter/version.h | 4 | ||||
| -rw-r--r-- | libavfilter/vf_blackdetect.c | 209 |
6 files changed, 268 insertions, 2 deletions
@@ -11,6 +11,7 @@ version next: - ID3v2 attached pictures reading and writing - WMA Lossless decoder - bluray protocol +- blackdetect filter version 0.10: diff --git a/doc/filters.texi b/doc/filters.texi index 238401a0d2..2c646cbe46 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -761,6 +761,60 @@ video, use the command: ass=sub.ass @end example +@section blackdetect + +Detect video intervals that are (almost) completely black. Can be +useful to detect chapter transitions, commercials, or invalid +recordings. Output lines contains the time for the start, end and +duration of the detected black interval expressed in seconds. + +In order to display the output lines, you need to set the loglevel at +least to the AV_LOG_INFO value. + +This filter accepts a list of options in the form of +@var{key}=@var{value} pairs separated by ":". A description of the +accepted options follows. + +@table @option +@item black_min_duration, d +Set the minimum detected black duration expressed in seconds. It must +be a non-negative floating point number. + +Default value is 2.0. + +@item picture_black_ratio_th, pic_th +Set the threshold for considering a picture "black". +Express the minimum value for the ratio: +@example +@var{nb_black_pixels} / @var{nb_pixels} +@end example + +for which a picture is considered black. +Default value is 0.98. + +@item pixel_black_th, pix_th +Set the threshold for considering a pixel "black". + +The threshold expresses the maximum pixel luminance value for which a +pixel is considered "black". The provided value is scaled according to +the following equation: +@example +@var{absolute_threshold} = @var{luminance_minimum_value} + @var{pixel_black_th} * @var{luminance_range_size} +@end example + +@var{luminance_range_size} and @var{luminance_minimum_value} depend on +the input video format, the range is [0-255] for YUV full-range +formats and [16-235] for YUV non full-range formats. + +Default value is 0.10. +@end table + +The following example sets the maximum pixel threshold to the minimum +value, and detects only black intervals of 2 or more seconds: +@example +blackdetect=d=2:pix_th=0.00 +@end example + @section blackframe Detect frames that are (almost) completely black. Can be useful to diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 6e7379c492..df3a27f2b9 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -48,6 +48,7 @@ OBJS-$(CONFIG_ABUFFERSINK_FILTER) += sink_buffer.o OBJS-$(CONFIG_ANULLSINK_FILTER) += asink_anullsink.o OBJS-$(CONFIG_ASS_FILTER) += vf_ass.o +OBJS-$(CONFIG_BLACKDETECT_FILTER) += vf_blackdetect.o OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o OBJS-$(CONFIG_BOXBLUR_FILTER) += vf_boxblur.o OBJS-$(CONFIG_COPY_FILTER) += vf_copy.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 487738ae5f..f6230be3c1 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -56,6 +56,7 @@ void avfilter_register_all(void) REGISTER_FILTER (ANULLSINK, anullsink, asink); REGISTER_FILTER (ASS, ass, vf); + REGISTER_FILTER (BLACKDETECT, blackdetect, vf); REGISTER_FILTER (BLACKFRAME, blackframe, vf); REGISTER_FILTER (BOXBLUR, boxblur, vf); REGISTER_FILTER (COPY, copy, vf); diff --git a/libavfilter/version.h b/libavfilter/version.h index 0435d57376..1eedd5423a 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -29,8 +29,8 @@ #include "libavutil/avutil.h" #define LIBAVFILTER_VERSION_MAJOR 2 -#define LIBAVFILTER_VERSION_MINOR 62 -#define LIBAVFILTER_VERSION_MICRO 101 +#define LIBAVFILTER_VERSION_MINOR 63 +#define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ LIBAVFILTER_VERSION_MINOR, \ diff --git a/libavfilter/vf_blackdetect.c b/libavfilter/vf_blackdetect.c new file mode 100644 index 0000000000..db94794979 --- /dev/null +++ b/libavfilter/vf_blackdetect.c @@ -0,0 +1,209 @@ +/* + * Copyright (c) 2012 Stefano Sabatini + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * Video black detector, loosely based on blackframe with extended + * syntax and features + */ + +#include <float.h> +#include "libavutil/opt.h" +#include "libavutil/timestamp.h" +#include "avfilter.h" +#include "internal.h" + +typedef struct { + const AVClass *class; + double black_min_duration_time; ///< minimum duration of detected black, in seconds + int64_t black_min_duration; ///< minimum duration of detected black, expressed in timebase units + int64_t black_start; ///< pts start time of the first black picture + int64_t black_end; ///< pts end time of the last black picture + int black_started; + + double picture_black_ratio_th; + double pixel_black_th; + unsigned int pixel_black_th_i; + + unsigned int frame_count; ///< frame number + unsigned int nb_black_pixels; ///< number of black pixels counted so far +} BlackDetectContext; + +#define OFFSET(x) offsetof(BlackDetectContext, x) +static const AVOption blackdetect_options[] = { + { "d", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX}, + { "black_min_duration", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX}, + { "picture_black_ratio_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1}, + { "pic_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1}, + { "pixel_black_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1}, + { "pix_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1}, + { NULL }, +}; + +static const char *blackdetect_get_name(void *ctx) +{ + return "blackdetect"; +} + +static const AVClass blackdetect_class = { + .class_name = "BlackDetectContext", + .item_name = blackdetect_get_name, + .option = blackdetect_options, +}; + +#define YUVJ_FORMATS \ + PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ444P, PIX_FMT_YUVJ440P + +static enum PixelFormat yuvj_formats[] = { + YUVJ_FORMATS, PIX_FMT_NONE +}; + +static int query_formats(AVFilterContext *ctx) +{ + static const enum PixelFormat pix_fmts[] = { + PIX_FMT_YUV410P, PIX_FMT_YUV420P, PIX_FMT_GRAY8, PIX_FMT_NV12, + PIX_FMT_NV21, PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV411P, + YUVJ_FORMATS, + PIX_FMT_NONE + }; + + avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts)); + return 0; +} + +static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) +{ + int ret; + BlackDetectContext *blackdetect = ctx->priv; + + blackdetect->class = &blackdetect_class; + av_opt_set_defaults(blackdetect); + + if ((ret = av_set_options_string(blackdetect, args, "=", ":")) < 0) { + av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args); + return ret; + } + + return 0; +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + BlackDetectContext *blackdetect = ctx->priv; + + blackdetect->black_min_duration = + blackdetect->black_min_duration_time / av_q2d(inlink->time_base); + + blackdetect->pixel_black_th_i = ff_fmt_is_in(inlink->format, yuvj_formats) ? + // luminance_minimum_value + pixel_black_th * luminance_range_size + blackdetect->pixel_black_th * 255 : + 16 + blackdetect->pixel_black_th * (235 - 16); + + av_log(blackdetect, AV_LOG_INFO, + "black_min_duration:%s pixel_black_th:%f pixel_black_th_i:%d picture_black_ratio_th:%f\n", + av_ts2timestr(blackdetect->black_min_duration, &inlink->time_base), + blackdetect->pixel_black_th, blackdetect->pixel_black_th_i, + blackdetect->picture_black_ratio_th); + return 0; +} + +static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) +{ + AVFilterContext *ctx = inlink->dst; + BlackDetectContext *blackdetect = ctx->priv; + AVFilterBufferRef *picref = inlink->cur_buf; + int x, i; + const uint8_t *p = picref->data[0] + y * picref->linesize[0]; + + for (i = 0; i < h; i++) { + for (x = 0; x < inlink->w; x++) + blackdetect->nb_black_pixels += p[x] <= blackdetect->pixel_black_th_i; + p += picref->linesize[0]; + } + + avfilter_draw_slice(ctx->outputs[0], y, h, slice_dir); +} + +static void end_frame(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + BlackDetectContext *blackdetect = ctx->priv; + AVFilterBufferRef *picref = inlink->cur_buf; + double picture_black_ratio = 0; + + picture_black_ratio = (double)blackdetect->nb_black_pixels / (inlink->w * inlink->h); + + av_log(ctx, AV_LOG_DEBUG, + "frame:%u picture_black_ratio:%f pos:%"PRId64" pts:%s t:%s type:%c\n", + blackdetect->frame_count, picture_black_ratio, + picref->pos, av_ts2str(picref->pts), + av_ts2timestr(blackdetect->black_start, &inlink->time_base), + av_get_picture_type_char(picref->video->pict_type)); + + if (picture_black_ratio >= blackdetect->picture_black_ratio_th) { + if (!blackdetect->black_started) { + /* black starts here */ + blackdetect->black_started = 1; + blackdetect->black_start = picref->pts; + } + } else if (blackdetect->black_started) { + /* black ends here */ + blackdetect->black_started = 0; + blackdetect->black_end = picref->pts; + + if ((blackdetect->black_end - blackdetect->black_start) >= blackdetect->black_min_duration) { + av_log(blackdetect, AV_LOG_INFO, + "black_start:%s black_end:%s black_duration:%s\n", + av_ts2timestr(blackdetect->black_start, &inlink->time_base), + av_ts2timestr(blackdetect->black_end, &inlink->time_base), + av_ts2timestr(blackdetect->black_end - blackdetect->black_start, &inlink->time_base)); + } + } + + blackdetect->frame_count++; + blackdetect->nb_black_pixels = 0; + avfilter_end_frame(inlink->dst->outputs[0]); +} + +AVFilter avfilter_vf_blackdetect = { + .name = "blackdetect", + .description = NULL_IF_CONFIG_SMALL("Detect video intervals that are (almost) black."), + .priv_size = sizeof(BlackDetectContext), + .init = init, + .query_formats = query_formats, + + .inputs = (const AVFilterPad[]) { + { .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_input, + .draw_slice = draw_slice, + .get_video_buffer = avfilter_null_get_video_buffer, + .start_frame = avfilter_null_start_frame, + .end_frame = end_frame, }, + { .name = NULL } + }, + + .outputs = (const AVFilterPad[]) { + { .name = "default", + .type = AVMEDIA_TYPE_VIDEO }, + { .name = NULL } + }, +}; |